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Multi-Channel Gustometer


Multi-Channel Gustometer Kevin A. Johnson Advisor: Dr. David H. Zald Neuroimaging Engineer: Patrick Henry Multi-Channel Gustometer General Design Objective Device to ... – PowerPoint PPT presentation

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Title: Multi-Channel Gustometer

Multi-Channel Gustometer
  • Kevin A. Johnson
  • Advisor Dr. David H. Zald
  • Neuroimaging Engineer Patrick Henry

Multi-Channel Gustometer
  • General Design Objective
  • Device to present an array of taste stimuli.
  • Delivery of stimuli must be in a controlled
  • Intended for functional neuroimaging (fMRI)
    studies on human participants.
  • Adaptable to a variety of experiment protocols.

Gustometer Background
  • Multi-channel gustometers have been used for
    psychophysical studies on monkeys.
  • (Reilly et al. 1994) ? Computer Automated
  • Current gustometers for neuroimaging provide
    only a few (generally 1 or 2) taste stimuli.
    (Zald et al. 2000 2002)
  • ? NOVELTY Multi-channel gustometer for
    functional neuroimaging.

fMRI Background
  • Strong magnet field environment (3T).
  • ? Safety and interference considerations.
  • Time course of neural-physiological response to
    be measured is quite rapid.
  • ? Requires precise control of stimuli delivery
    and response measurement.
  • Imaging technique is very sensitive to physical
    movement of participant.
  • ? Need passive reception of stimuli.

Specification Demands
  • 1. fMRI Friendly
  • No ferrous materials within 10 ft. of participant
    (preferably farther than 10ft).
  • Minimal electronics close to subject.
  • Note In past experiments, this demand has been
    achieved by delivering fluid stimulus through
    extended tubing.

Specification Demands (cont.)
  • Ability to deliver up to 10 different fluids.
  • Ability to deliver from 0.5 5 ml discrete
    boluses of liquid.
  • (Accuracy ? 15)
  • Safety consider amount intake.

Specification Demands (cont.)
  • Ability to switch in a relatively constant flow
    (no more than 250 ms pause) from one stimulus to
  • Note It is fine if there is a time lag (lt 1 s)
    between a stimulus pulse (stimulus switch) and
    the time it reaches the participant, as long as
    the timing is consistent (? 250 ms).

Specification Demands (cont.)
  1. A fixed flow rate of 0.5 ml/s is acceptable.
  2. Ability to deliver up to 50 cc in a session for
    each stimulus, with one stimulus (for saline)
    able to deliver more (up to 200 cc).
  3. Ability to exchange stimulus containers quickly
    (exchange all 10 in less than 5 minutes).

Specification Wishes
  1. Expandable to deliver more than 10 different
  2. Ability to vary flow rate (as low as .25 ml/s or
    as high as 1 ml/s).
  3. Easily to sanitize (contamination resistant).

Specification Wishes (cont.)
  • Easily portable.
  • Protective covering.
  • User-friendly.
  • Quick development time of device.
  • 8. Reasonable cost.

Innovative Approaches?
  • Electrical Simulation of Taste?
  • ? Perceptual Problems
  • Single pump with stimuli prearranged in single
  • ? Contamination Problems
  • Solid taste stimuli?
  • ? Numerous Problems
  • Pneumatic-Controlled Pumps Closer
  • ? More components, re-setup time
  • ? Use concept, possible alternative

(No Transcript)
Probable Merging Unit Configuration
Stimulus Delay
  • Delay (Distance)/(Speed)
  • Max Delay 1 second
  • Max Pump Speed 3. 06161 cm/mn (?)
  • ? Max Tubing Distance

Current Status
  • Verified pump/syringe specifications.
  • Verified pump control via computer.
  • Need to finalize merging design and order tubing
  • ? Spoke concept.